More than 20 illegal immigrants have been charged with document and benefit fraud, officials announced Thursday, after a Boston-based sweep designed to crack down on the means many illegal immigrants use to live and remain in the U.S.

All told, the feds netted 25 people — 21 of them illegal immigrants — in the sweep, including a convicted murderer who escaped from Puerto Rican prison and had been living under a different name in Massachusetts, and a drug trafficker who authorities say stole the identity of a U.S. citizen displaced by last year’s hurricanes in Puerto Rico.

That person was receiving unemployment benefits and living in taxpayer-funded housing, Attorney General Jeff Sessions said.

Identity fraud is one of the seamy sides of illegal immigrant, with many of the estimated 11 million unauthorized migrants in the U.S. having stolen or illicitly bought someone else’s identity, then used it to get a job or obtain benefits.

The Obama administration downplayed the effects of identity fraud, issuing guidance saying it wouldn’t be held against illegal immigrants seeking protections such as the DACA deportation amnesty.

Mr. Sessions said they’re changing that mentality.

“Across this city and across America, teachers, truck drivers, and construction workers are going to work and paying taxes that are being stolen from the public treasury by fraudsters and criminals,” he said in announcing the charges against 25 people.

Most of the 25 are Dominicans who stole identities of U.S. citizens in Puerto Rico, an American territory.

One of those citizens lost his house in the hurricanes last year and applied for government assistance. He was told he was already getting a subsidy — in Massachusetts, Mr. Sessions said.